- Black Bart was a full-fledged WWF jobber for a year, not far removed from being named World Class' first "World" champion

I remember this because it made me think
"Shit, this guy was the WCCW 'World" Champion and now he can't beat anyone in the WWF"
and
"If he's willing to job so much for the WWF, how bad was the pay in WCCW that this seemed like a better alternative?"

khawk wrote: - Black Bart was a full-fledged WWF jobber for a year, not far removed from being named World Class' first "World" champion

I remember this because it made me think
"Shit, this guy was the WCCW 'World" Champion and now he can't beat anyone in the WWF"
and
"If he's willing to job so much for the WWF, how bad was the pay in WCCW that this seemed like a better alternative?"
Gary Hart's autobiography goes into detail about how bad WCCW was during the Black Bart era. Although certainly bitter that he had been pushed out as booker by Ken Mantell, it was clearly every bit the shit-show that Hart claims. Seceding from the NWA and then going with Black Bart of all people when other World champions were Hogan and Flair, it was just a disaster and the loyal Dallas fans were pretty shell-shocked by David and Mike's deaths by that time and were checked out, as was Fritz.

I remember seeing that picture of Ted and Chris in an apter mag around the time Chris debuted in WCW and being pissed that the WWF didn’t sign him. (I was a WWF loyalist at that point). I didn’t know much about anything as a 16 year old fan without internet but it only took one WCW match for me to see Chris was badass.

____________________"Beginning this week, Nitro is going head-to-head with Thunder in Australia" - The Wrestling Observer Newsletter: January 22, 2001

Just to be fair with World Class regarding their world champion, I believe Rick Rude was the champ when Fritz left the NWA, which wasn’t a terrible move by any means. Rude and Pringle were fun together. That’s when the shit went down after a few months. Rude bolted for Crockett, and they went with Chris Adams, which also wasn’t bad. At some point in the summer, Adams was either arrested or finally had to serve jail time for beating up the stewardess. That’s when Fritz was in a bind and they gave it to Black Bart (may have even been a phantom change). Black Bart had been Mid Atlantic champion up until a few weeks earlier when he lost to Rob Garvin. It was obvious he was going to be a transitional champion to Kevin at the Cotton Bowl show. I’m doing this all by memory, but I don’t think Black Bart held the belt for more than 4-6 weeks until the Cotton Bowl. It’s not like Fritz severed ties with the NWA with the sol purpose of strapping Bart and riding him to the moon. Just typical World Class circumstances happened and lots of bad luck.

____________________"Well, maybe I like the nightlife just a little bit more than I like the damn gym, jack! And when you're makin' $500,000 a year, there ain't no reason to change what you're doing." - Dusty Rhodes, 1/4/1986

- Black Bart was a full-fledged WWF jobber for a year, not far removed from being named World Class' first "World" champion

Technically, Rick Rude was the first World Class "World" Champion, when they decided to go on their own in the Spring of 1986. Chris Adams then beat him, over the summer. Black Bart then "beat" Adams in what I believe was a phantom title switch, circa September 1986. Didn't last long, as Kevin Von Erich soon beat him for the championship.
Bart as a heel champ was a flop, but he was in and out of World Class, UWF and other places for a few years, afterwards. He went to the WWF in 1990. It's splitting hairs, but it's like saying "former NWA World Champion Ronnie Garvin was jobbing in the WWF within 3 years".
I think one point of confusion about Bart being World Class's "first" World champ is that they started running on ESPN in the late summer or fall of 1986. These were current, first-run shows and not the "Legends of World Class" package that came later.

Here's one I can add: in 1998, the BUSHWHACKERS appeared in ECW.
Junkyard Dog also appeared for ECW sometime in the mid to late 90's. I think it was more of a special appearance and don't believe he actually wrestled.

Erick Von Erich wrote: Junkyard Dog also appeared for ECW sometime in the mid to late 90's. I think it was more of a special appearance and don't believe he actually wrestled.

JYD appeared as part of an introduction of legends when they held a PPV in Marietta, Georgia. This was the night when JYD and New Jack had a back stage fight over some money they JYD allegedly owed to New Jack. JYD had a band-aid on his face when he came out, and he was wearing an ECW t-shirt, since his shirt was bloody after the fight.